| Number | Date | Country | Kind |
|---|---|---|---|
| 3940792 | Dec 1989 | DEX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4835246 | Tsai et al. | May 1989 | |
| 4892921 | Tsai et al. | Jan 1990 | |
| 4910293 | Vekita et al. | Mar 1990 | |
| 5001217 | Tsai et al. | Mar 1991 |
| Number | Date | Country |
|---|---|---|
| 1-256534 | Oct 1989 | JPX |
| Entry |
|---|
| Abstract CA115(26):280694x. |